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• What is meant by a tissue?

  A tissue is a group of cells with a similar structure and function.
• What is an organ?

  An organ is a group of tissues working together for a specific function.
• What is an organ system?

  An organ system is a group of organs that work together to form organisms.
• What are the main organs in the digestive system?

  The main organs in the digestive system include the mouth, esophagus, stomach, small intestine, and large intestine.
• What are the three main nutrients found in food?

  The three main nutrients are carbohydrates, proteins, and lipids (fats).
• Why must large food molecules be digested?

  Large food molecules must be digested because they are too large to be absorbed into the bloodstream.
• How are large food molecules broken down during digestion?

  Large food molecules are broken down into small molecules by enzymes.
• What begins the digestion of starch in the mouth?

  Enzymes in the saliva begin to digest starch into smaller sugar molecules.
• What role does hydrochloric acid play in the stomach?

  Hydrochloric acid helps enzymes to digest proteins in the stomach.
• What happens to food in the stomach?

  The churning action of the stomach muscles turns food into a fluid, increasing the surface area for enzymes to digest.
• What chemicals are released into the small intestine from the liver and pancreas?

  The pancreas releases enzymes, and the liver releases bile into the small intestine.
• What is the function of bile in digestion?

  Bile helps to speed up the digestion of lipids and neutralizes the acid from the stomach.
• How are small food molecules absorbed in the small intestine?

  Small food molecules are absorbed into the bloodstream either by diffusion or by active transport.
• What happens in the large intestine during digestion?

  Water is absorbed into the bloodstream in the large intestine.
• What is released from the body at the end of digestion?

  Feces is released from the body at the end of digestion.
• How are the products of digestion used by the body?

  The products of digestion are used by the body to build new carbohydrates, lipids, and proteins.
• What is one use of glucose produced during digestion?

  Some of the glucose produced is used in respiration.
• What are the main functions of the different organs in the digestive system?

  • Mouth: Chews food and begins starch digestion.
  • Esophagus: Transports food to the stomach.
  • Stomach: Digests proteins and churns food into fluid.
  • Small Intestine: Continues digestion and absorbs nutrients.
  • Large Intestine: Absorbs water and releases feces.
• What should you remember about the digestive system for revision?

  • Large food molecules are digested into smaller molecules.
  • Products of digestion are absorbed into the bloodstream.
• What should you be able to describe by the end of the video on enzymes in the digestive system?

  The enzymes in the digestive system and the role of bile
• What is the function of enzymes in the digestive system?

  They catalyze chemical reactions and speed them up
• What are enzymes made of?

  Large protein molecules
• What is the active site of an enzyme?

  It is the groove on the enzyme's surface where the substrate attaches
• What is a substrate in the context of enzymes?

  The molecule that the enzyme breaks down
• What does the lock and key theory describe?

  It describes how the substrate must fit perfectly into the active site of the enzyme
• What type of enzymes break down proteins?

  Proteases
• Where are proteases found in the digestive system?

  In the stomach and pancreatic fluid in the small intestine
• What are proteins made of?

  Long chains of amino acids
• What happens to proteins during digestion?

  Protease enzymes convert proteins back to individual amino acids
• What type of enzymes break down carbohydrates?

  Carbohydrases
• What is the specific enzyme that breaks down starch?

  Amylase
• What is the structure of starch?

  A chain of glucose molecules
• Where is amylase found?

  In saliva and pancreatic fluid
• What is the structure of a lipid molecule?

  A molecule of glycerol attached to three fatty acids
• What enzyme digests lipids?

  Lipase
• What are the products of lipid digestion?

  Glycerol and fatty acids
• Where is lipase found?

  In pancreatic fluid and the small intestine
• What is the role of bile in lipid digestion?

  Bile helps to speed up the digestion of lipids but is not an enzyme
• How does bile aid in lipid digestion?

  Bile emulsifies large lipid droplets into smaller droplets
• Where is bile made and stored?

  Bile is made in the liver and stored in the gallbladder